1. Field of the Invention
The present invention relates to apparatuses and methods for automatically analyzing a specimen and, more particularly, to apparatuses and methods for automatically analyzing a specimen for clinical assays utilizing a blood coagulation reaction and immunoreaction.
2. Description of Related Arts
In clinical assays utilizing a blood coagulation reaction and immunoreaction, measurements are repeatedly performed on a specimen for plural assays, or a so-called reflex test is performed in which, for example, fundamental assays such as for the prothrombin time (PT) and activated partial thromboplastin time (APTT) are first performed on a specimen in a primary screening and the mount of fibrinogen (Fbg) of the specimen is then measured or not measured in a secondary screening depending on the result of the primary screening.
Further, if the result of an assay of a specimen is within a predetermined abnormal value range or out of a predetermined normal value range due to malfunction of an analyzer, deterioration of reagents or the like, the assay has to be performed again on the specimen.
In general, where a re-assay or plural measurements are required to be performed on one specimen, the specimen is dispensed from a particular sample vial to analysis means.
In prior arts, where a plurality of specimens in sample vials placed on a rack are automatically assayed, a particular specimen to be subjected to a re-assay or plural measurements is selectively sampled from the corresponding sample vial and dispensed to the assay means.
However, some assays take several minutes to several dozens minutes, requiring a long time after the dispensing of a specimen to obtain measurement results. Therefore, when it is determined that a particular specimen has to be re-assayed, the rack accommodating a sample vial which contains the specimen may already be transported to the next analyzer.
In such a case, the rack accommodating the sample vial has to be returned to a predetermined position, and then the sample vial which contains the specimen to be re-assayed is searched for. This may require an extra time and, in the worst case, the re-assay may become impossible.
In addition, an apparatus adapted to return a rack accommodating sample vials to a predetermined position for re-assay may be large-scale and complicated, and thereby costly.
Therefore, it is desired to repeatedly use a specimen once taken into an analyzer for re-assay or plural measurements.